Transformer.



J. BURKE.

TRANSFORMER.

APPLICATION FILED osc. 10,,1910.

Patented Jul 6, 1915.

To all whom it may concern UNITED- sr rr s PATENT clarion.

.rmns mmxn, or mun, PENNSYLVANIA, essrenoa To sum A conromrron or rmmsrnvnmn.

Be it known that-I, JAMES BURKE, a citizen of the United States, residing at Erie, inthe county of Erie and- State of Pennsylvania, have mvented certain new and useful Improvements in Transformers, of which the following is a full, clear, and exact specification.

This'invention relates to transformers, 1nduction coils, and the like, and. pertains par- I ti'cularly to the constructionand arrangement of the" cores of transformers and the like.

My invention relates further to the method of-censtructing the same.

More specifically, my invention relates to cores formed. of laminae or sheets of -magnetic material, said lamina or sheets being constructed to insure effectively good magnetic contact at the joints of the-laminae or sheets so that allair gaps are substantially avoided.

By my invention, I construct a transformer core applicable to transformers having any desired number of legs any of which may either be provided or not provided with transformer winding or windings as desired,

and which legs are united at their ends by end pieces in which the laminae are continuous throughout the length of the end pieces, while at the same time obtaining overlapping form of joints with the attendant advantages of such form of joints.

My invention will be more fully understood from the following description and accompanying drawings, in which- Figure 1 is a perspective view. of assembled legs and end pieces constituting a core,

embodying one form of my invention. Fig. 2 is an end elevation of an individual core leg of the same; and Fig. 3 is a side elevation of the same.

end members uniting the legs at their respective ends. Taking the form, of leg construction shown in Figs. 2 and 3 the laminae are arranged-one adjacent the other to provide projecting portions at both ends. In

the specific form shown in said Figs. 2 and 3, the laminae 6, 7 are of equal length, alternatively arranged to provide equal projecting portions at the two ends. It is not necessary that'said laminae 6, 7 be of the same dimensions, since, as will be readily under-. stood, eachleg may be formed of alternate TRANSFORMER.

' Patented July 6,1915.

sets of short and longer laminae and .staggered relatively to each other to provide nnno'rnrc comremr,

either equal or unequal projecting portions,

which portions, as will be later more fully seen, overlap corresponding lateral projecting portions of the end members. Theend pleces or members are built up of 'continuous laminae extending from one end-of one leg to a corresponding end of the other leg "or corresponding ends of the remaining legs.

As shown in Fig. 1, the continuous end members 4, 5 extend from the upper and lower ends, respectively, of leg 1 across the ends of intermediate leg 2 to the corresponding ends of outermost leg 3. These members 4, 5, as

shown, comprise each two sets of laminae 9,

-10 of different widths, arranged one adjacent'the other to give a lateral stagger, the difference in Width in this specific form being equal to the amount of stagger or length of the projecting portionsof the laminae on the ends of the legs 1, 2, 3 at which they are positioned. Said end pieces or members 4, 5 may be built up of laminae of the same dimensions, whereby projecting portions of alternate laminae will extend upwardly in the upper end member 4, and likewise downwardly in the lower end memben 5. In general, assuming the effective total amount of magnetic material of the laminae tobe proper according to the requirements of the transformer, each end member is built up of laminae arranged in sets to provide lateral inter-lamellar spaces into which the projecting. portions at one end 1 of each leg make a good fit, each lamina of continuous material of each end piece being brought into good magnetic contact edge for edge with the isoplanar lamina of each leg, whereby the projecting portions at the ends of the legs make overlapping joints with the lateral projecting portions of the end pieces. The

amount of stagger between adjacent sheets or laminae of the legs and end pieces may be varied, but in all cases the'amountoverlapping is preferably made small, but suflicient to give the necessary grip andstrength. Any suitable means may be employed for binding the laminae of the end members, and

I have shown strips 11 of wood or other suitable material applied to the outermost laminae on the opposite sides of each end piece, and bound in such position by cord 12.

In assembling my transformer, the legs are first constructed as above stated, the

aoi

" ber of legs, whether or not the same are prolaminaeof each individual leg being-bound I together'as a unit by tape or-other suitable bandage. These legs are then placed atproper distances fromeach other with corr onding projections in orapproximately uniting the corresponding ends of the 'legs by the continuous end pieces, is to build the end pieces in sequence, inserting first those laminae of one end piece, say' laminae-.10 of end piece 4, into the isoplanar grooves of bringing .eachflamina ternatelaminae .10, and likewise positioned in good magnetic .contact with; the upper edges oflaminae 6 of the legs 1, 2,-3. The end iece 5 is built in a similar manner. It

I will e understood that in such cases where the transformer winding or windings are a wound about any desired leg, such as indicated in 8, itis convenient to Wind .the same before either end piece is positioned; when the winding orwmdings are of the slip-- on type, the same can be slipped on the desired leg at any-"time before the last end' piece is positioned. It will thus beseen that my transformer is applicable for any numvided with a transformer winding, 'with'the v advantages of overlapping joints, while having continuous strips throughout thelength of the end pieces, and at the same time securing rigidity in construction and ease and e sameplane. My preferred method of simplicity in assembling and ec'onomyof materlal.

Having thus described my invention, I j s 40 declare that what I claim as new and desire to secure by Letters Patent; is, v

1, A transformer core of magnetic matea rial comprising a plurality of legs, each of said legs being built up of laminae, each lamina thereof being'a rectangle, and said laminae being assembled to form projections and intermediate grooves at the ends ofthe le s, and-laminated end pieces, each lamina o the end pieces extending to the outermost edges 0 the legs, and the laminae ofthe end pieces assembled 'to form projections and grooves which face and fit the projections and grooves of the ends of the legs.

2. A transformer core of magnetic mate rial comprising a plurality offlle'gs', each ofsaid legs being built up of laminae, each laminae being assembled tovform projections and intermediate grooves at the ends ofv the legs, and laminated end pieces, eachlamina lamina'thereof being a rectangle, andsaid of the end pieces being a rectangle and extending" to the outermost edges of'the legs, I

the laminae of the-end pieces being assembled to form projections and grooves. which face and fit theprojections of the end of the legs.

. JAMES BURKE.

Witnesses p HENRY J. Looms, Gno. N. KERR.

In testimony whereof I aflix my signature, in presence of two witnesses. 

